Overview

In 1791, the Swiss physicist Pierre Prévost (1751-1839) published a theory of heat exchanges, which described how heat is transferred from one object to another. This theory, which is still accepted today, formed a basis for other scientists who studied heat transfer. Prévost also supported the caloric theory of heat—the idea that heat is a liquid. His work helped to convince other scientists of caloric theory, and it was not until late in the 1800s that this idea was finally disproved.

Background

In the eighteenth century, certain phenomena, such as heat, light, electricity, and magnetism, were considered to be imponderable fluids. Scientists used the term imponderable to mean "weightless." Imponderable fluids were supposedly composed of weightless, invisible particles that could flow from one object to another. (It is now known that such fluids do not exist.) Scientists thought that...